This invention relates to a linear motor driven actuator (linear actuator) used to position the read/write transducers of a disk drive, and more particularly the invention relates to a disk drive incorporating one or more 3.5-inch-diameter or 5.25-inch-diameter magnetically coated disks.
In the past, more compact disk drives have been made possible by utilizing an actuator wherein the linear motor consisted of dual magnetic structures and a single coil. Such linear actuators have been manufactured and shown by Cipher Data Products of San Diego, California and have been manufactured and sold by Sequential Information Systems of Elmsford, New York and also by Western Dynex of Phoenix, Arizona. Other manufacturers have since manufactured linear actuators incorporating dual magnetic structures and either a single coil or dual coils. These linear actuators, especially when configured for use in 5-1/4-inch and smaller disk drives, have suffered from several problems. They are comparatively complex and therefore difficult and expensive to manufacture. In addition, considerable electrical power is required to move and control the high-inertia load presented by the actuator's relatively heavy carriage-coil assembly.
There is therefore a need for a new and improved linear actuator that (a) has performance equivalent to or better than currently available products, (b) is simpler and less expensive to manufacture, (c) can be incorporated into disk drives having the industry-standard form factor, and (d) accomplishes these objectives while substantially reducing electrical power consumption.